Ran out of fuel 1/2 way around the block - duh. Looking for fuel line / return routing advice. (1 Viewer)

[JustJay]

Looking for some advice / education / direction on how to make any modifications I need to re-route fuel lines as I near the end of reassembly. Looked around and other threads but couldn't find what I was looking for.

Here's the summary for anyone interested.
Bought vehicle a couple of years ago. Much disassembly and now nearing getting it back to functioning. Took it out for a drive after it spent the winter being worked on in the garage. During the project I took out and completely emptied the gas tank. Didn't want to deal with fuel in the tank over the winter so as I messed around with things I hooked up a temporary jerry can just before the fuel filter. Fired it up today and went for a ride around the block. Well, I should say 1/2 around the block when I ran out of the 1 gallon of gas that I had just put in the can! After scratching my head a bit I decided 1 - I'm either getting horrible gas mileage 2- have a significant leak 3- the fuel is being routed somewhere. Got out of the truck and shook it back and forth at the passenger side and sure enough could hear fuel sloshing around it what I thought was an empty tank. Concluded its filling back up with fuel via a return line.

Now the particulars -
72' 40
78' 2F engine
Weber carb
At one time someone had installed a second fuel tank, which I removed and filled when we re-painted the body.

My question is best way to move forward with finalizing fuel lines? Seems like I could -
1 - Remove the temp jerry can and simply hook the hose back to take fuel from the tank and use the return line as plumbed (not sure I like that as it seems like there is an awful lot of extra fuel moving around via the return.
2- Abandon the return side of the pump via a plug.
3 - Get a different pump without the return side.
4 - Something else?

Followup question - You can see in the schematic that there is an abandoned / open line that goes from the top of the tank to the engine bay. Seems like a vent of some kind. Am I correct? Is there an end of some kind for that (other than the yellow tape that is currently on it?!?)

 

[pb4ugo]

Looking at your tank and pump connections, it looks like it already has a return line. It also looks like a later model gas tank.

 

[brian]

Yeap 60 series pump with the return line on it....acts like a pressure relief so the carb doesn't see as much fuel pressure.

 

[JustJay]

Yeap 60 series pump with the return line on it....acts like a pressure relief so the carb doesn't see as much fuel pressure.

Ok, so sounds like I can leave the piping as-is with return and no harm done.?.

 

[Steamer]

it seems like there is an awful lot of extra fuel moving around via the return.

For curiosity’s sake, you could just temporarily plumb the return to the jerry can to see just how much gets returned. And you could make it all the way around block.

 

[JustJay]

Looking at your tank and pump connections, it looks like it already has a return line. It also looks like a later model gas tank.

For curiosity’s sake, you could just temporarily plumb the return to the jerry can to see just how much gets returned. And you could make all the way around block.

I guess that's what got me thinking. It only ran for maybe a few minutes and went through a full gallon of fuel. Seems like a lot of gas getting returned & just cycled back through.?.

 

[Steamer]

Seems like a lot of gas getting returned & just cycled back through.?.

Yup, it's normal. That's how it maintains the right pressure to the carb during various fuel demands like WOT going uphill vs idle.

 

[JustJay]

Yup, it's normal. That's how it maintains the right pressure to the carb during various fuel demands like WOT going uphill vs idle.

Good to know. Will keep the plumbing the same. Thanks for the help!

 

[FJ907Warrior]

Here is a photo of my tank vent connections, my 'to carb' connection is the center connection on the side facing the driver.

Hope that helps. If you need a evap I have a few spare.

 

[FJ907Warrior]

Also noticing this is the later fuel pump, and a late 70s 2F... Do you have the 1/4ish inch spacer between the engine block and pump?

 

[JustJay]

Not sure. I’ll have to run out and check on it. Eliminated temp can this afternoon (since there’s already gas in tank now) and started right up.

 

[River Bend]

Gas Tanks - FJ40/45 - https://www.coolcruisers.com/gastanfj19th.html
Cool Cruiser shows tank hook up and cutaway showing inside also.

 

[mattressking]

Very simple, I recommend following the factory diagram for a 75-79 2F which has a feed and return to the pump. The caveat is that you have a 80+ pump which means no return from carb, which is fine for you.

77241B is your feed line.
77277B is your return line.

Connect 77241B to In on pump. Connect 77277B to your return on pump. Make sure all lines are clear with compressed air.

The separator pictured is for a 75-79 truck so the three lines that normally go to the tank need to be adjusted to your evap system. Do you have the evap system from your truck still/charcoal canister?

 

[JustJay]

Very simple, I recommend following the factory diagram for a 75-79 2F which has a feed and return to the pump. The caveat is that you have a 80+ pump which means no return from carb, which is fine for you.

77241B is your feed line.
77277B is your return line.

Connect 77241B to In on pump. Connect 77277B to your return on pump. Make sure all lines are clear with compressed air.

The separator pictured is for a 75-79 truck so the three lines that normally go to the tank need to be adjusted to your evap system. Do you have the evap system from your truck still/charcoal canister?

View attachment 3585536

Thanks for info. So, looks like I've got the hoses that I have routed properly. However, seems like my system has been somewhat stripped down and simplified. I do not have a separator - It's been abandoned with the 2 plugs. Also, don't believe I have the evap / charcoal canister....

 

[mattressking]

Thanks for info. So, looks like I've got the hoses that I have routed properly. However, seems like my system has been somewhat stripped down and simplified. I do not have a separator - It's been abandoned with the 2 plugs. Also, don't believe I have the evap / charcoal canister....

I recommend using a charcoal canister and venting it properly.

Next steps:

1. Locate oem charcoal canister (two port)
2. Locate vapor separator for your '72.
3. Plum into tank according to oem diagram.
4. Ditch your weber for Aisan carb

 

[JustJay]

I recommend using a charcoal canister and venting it properly.

Next steps:

1. Locate oem charcoal canister (two port)
2. Locate vapor separator for your '72.
3. Plum into tank according to oem diagram.
4. Ditch your weber for Aisan carb

Well, now you've really sent me down a rabbit hole of research / education! Working on CC and separator. If anyone's got one, please reach out.

Flirted with the idea of swapping to Asian carb just a few months ago but got a bit overwhelmed by the knock-on effects and figured its been 2 years I've been working on getting this back together. At this point, let's work on getting it running and we can re-visit those "upgrades" or "back to stock-grades" down the road!

 

[JustJay]

Here is a photo of my tank vent connections, my 'to carb' connection is the center connection on the side facing the driver.

Hope that helps. If you need a evap I have a few spare.

View attachment 3584061

pm sent